This is a well known phenomenon and its great to see it verified anecdotally again. Some Econ professors also discovered this a while back and created stickk.c

This is a well known phenomenon and its great to see it verified anecdotally again. Some Econ professors also discovered this a while back and created stickk.com which allows you to put up a monetary punishment when you don't meet your agreed upon goal. The loss of money and having someone else keep you accountable greatly increases your motivation to achieve your goals. The money you pay if you don't meet your goal is donated to charity.